Flexible toolholder



Oct. 10, 1950 F. BURG 2,525,646

FLEXIBLE TOOLHOLDER Filed Feb. 12, 1946 2 Sheets-Sheet 1 I 1%.5 L vi \NVEN'TOR Fred Bury fatenteci Oct. 10,1950

UNITED STATES PATENT OFFICE FLEXIBLE TOOLHOLDER Fred Burg, Los Angeles, Calif: Applic'atioii- February 12, 1946, Serial No. 647,079

This invention relates to a tool holder, and particularly of the type described in an application filed on July 31, 1944, under Serial Number 547,358, now abandoned in the name of Fred Burg, and entitled Floating Tool Holder. This application is a continuation, in part, of the said former application.

When tools such as taps or reamers are operated, they require accurate centering with re spect to the work.

In many instances, such centering or guiding is facilitated by the use of guide bushings made from hardened material. However, in the event there is a slight angular or lateral misalignment of the tool, destructive vibrations, or whipping, can occur during the operation of the tool. These vibrations may cause intolerable variance in the direction or size of the aperture being machined.

Furthermore, when a tool is held in a stationary tool holder, as in a turret lathe, for reaming or cutting threads, a slight lateral misalignment of the tool is often difficult to avoid. Such misalignment may likewise cause highly undesirable vagaries in the performance of the tool.

It is one of the objects of this invention to prevent the occurrence of irregular and undesired effects that are due to lack of perfect alignment of the axis of the tool and the desired direction or axis of the aperture being machined.

It has been proposed to provide floating tool holders to overcome these objections; but such devices are expensive, and it is difficult to maintain them in proper working order.

It is accordingly another object of this invention to provide a simple and eifective flexible tool holder that can be easily serviced and that eliminates the undesirable vibration or whipping of the tool.

This invention possesses many other advantages, and has other objects which may be made more clearly apparent from a consideration of several embodiments of the invention. For this purpose there are shown a few forms in the drawings accompanying and forming part of the present specification. These forms will now be described in detail, illustrating the general principles of the invention; but it is to be understood that this detailed description is not to be taken in a limiting sense, since the scope of the invention is best defined by the appended claims.

Referring to the drawings:

Figure 1 is a longitudinal section of an embodiment of the invention;

Figs. 2, 3, and 4 are cross-sectional views, taken 12' Claims. (Cl. 27916) i i 2 respectively along planes indicated by lines 22,- 3-3, and 4-4 of Fig. I;

Fig. 5 is a view, similar to Fig. 1, of a modified form of the invention; and

Fig. 6 is a view, similar to Fig. l, ofa further modified form of the invention.

In the form shown in Figs. 1 to 4, a tap or reamer is to be supported in a tool holding member I. This tool holding member I is in driving relation to a tapered spindle 2 intended to be accommodated in an appropriate tapered socket in a drill press, or the like. The tool holding member is shown as provided with a tapered recess 3 for the accommodation of the shank of the tool.

The member 2 is provided with an enlarged hollow part defining a cylindrical chamber 4. Communicating with the inner end of this chamber 4 is a supplemental recess 5 of smaller diameter. The recess 5 and chamber 4 are co-axial and correspond to the axis of the tool. The member I extends into the chamber 4.

In order to provide a flexible connection between the members .I and 2, a resilient coupling 6 is inserted between the exterior cylindrical wall 1 of the member I and the interior surface of the chamber 4. The coupling 6 is in the form of an annular rubber plug completely filling the annular space around the surface 1. It may be made from either synthetic or natural rubber, preferably neoprene. It is in firm. engagement with the wall or annular chamber 4, as well as with the wall 1.

The manner in which the coupling 6 is confined in the chamber 4 will now be described. Adjacent the inner end of the chamber 4 the tool holding member I is provided with a circular flange 8. One surface of the flange rests against the inner end surface of the coupling 6. The opposite end surface of the coupling ,6 is engaged by a spring retaining ring 9 which is expanded into the peripheral groove Ill near the open end of the chamber 4. This ring 9 is capable of being compressed by an appropriate tool, by the aid of the ears ll (Fig. 2) formed at the ends of the ring 9, for removal and insertion.

The coupling 6 has considerable axial length so that a substantial resilient cushion is available between members I and 2.

In the event an excessive torque is required to drive the member I, a positive drive is provided.

For this purpose a number of radial slots l2 (Figs. 1 and 3) are formed in the periphery of the flange 8. Three slots are shown in this instance. Extending into the slots are driving pins 53. These pins are normally clear of the walls of the slots, as indicated most clearly in Figs. 1 and 3. They are held in appropriate driving positions in recesses formed in the bottom of the chamber L Since the coupling 6 is resilient, and since there is a clearance between the pins i3 and the slots 52, a substantial angular displacement of the tool holder l is permitted. Accordingly, whipping or undesired vibrations of the tool are obviated.

In order to ensure that positive pressure can be exerted on the tool, there is metal-to-metal contact between the members I and 2. For this purpose the member l carries at its inner end an extension M having an upper convex surface l5. This convex surface i5 is in contact with the inner boundary surface It of the recess 5.

An important feature of this construction is the facility with which the device can be assembled and dismantled should it be desirable to replace or repair any of the parts. Contraction of the retaining ring 9 and its removal permit the member i to be disengaged from the member 2, and coupling 5 may be removed and replaced as desired. Furthermore, the convex surface 55 permits a rolling action to take place between the members i and 2 Without interfering with the positive character of the pressure exerted upon the tool.

In use, the shank of the tool to be driven is inserted in the recess 3. Slight angular and lateral misalignment of the axis of the driving member 2 and of the aperture being machined does not interfere with accurate centering of the tool. Thus, there is no danger that the aperture will be distorted. by the machining operation.

In the form of the invention illustrated in Fig. 5, lateral and angular misalignments are again compensated for by the provision of a flexible cowpling ll. As before, this flexible coupling may be made of neoprene and is held within a chamber it formed at the end of the driving member is. The tool holding member 29 in this case is provided with a cylindrical recess 2i in which a tool may be held as by the aid of a radial set screw. The tool holding member 20 is provided with the flange 22 arranged to be positively driven by the pins 23.

Metal-to-metal contact in this instance between the driving and the driven member is provided by the interposition of a ball 26. Ihis ball 24 is in contact with the inner surface of a recess communicating with the chamber i8. It is also in contact with the upper surface of flange 22. In this instance both rolling action and lateral displacement are provided for by the aid of the ball.

This form may be used for holding tools in the turret or tool carriage of a lathe. Slight lateral misalignment between the axis of the tool and the axis of the aperture to be machined can be compensated for by the resilient nature of the coupling.

The form of the device shown in Fig. 6 is especially adapted to take care of lateral misalignment, although, to a limited extent, it is also capable of taking care of slight angular misalignment.

In this case the tool holder 26 has a cylindrical aperture 21 in which the shank of the tool can be held as by the aid of a radial set screw. As before, the resilient coupling 28 is held between the flange 29 at the inner end of the coupling 28 and a retaining ring. 36 adjacent the open end of the chamber 3|. A positive drive, as

before, is provided by one or more pins 32 accom modated in the clearance slots 33 extending radially at the periphery of the flange 29.

Metal-to-metal contact between the tool holder 2% and the driving member 3% is provided by a central boss 35. The lower surface of the boss 35 is in contact with the inner surface of the flange '29. Slight tilting between these two surfaces is permitted within the limits of the clearances provided. Substantial lateral sliding action between these two surfaces is also permitted.

The inventor claims:

1. In combination: a tool carrying member; a spindle member; one of said members having a part forming a chamber having a wall at one end and open at the other end, and the other member having a portion projecting into the chamber to form an annular-like space between the portion and the chamber; said members being bodily translatable in a lateral direction with respect to each other; a rubber insert filling said space and in simultaneous engagement with the side portions of both of said members; said portion and the member that forms the chamber being provided with means forming a rigid movable contact between the members to transmit forces in a substantially axial irection with relation to the members; said contact forming means being such that the members at the contact have limited freedom of lateral movement; and means forming a positive drive between the members.

2. In combination: a tool carrying member; a

spindle member; one of said members having a part forming a chamber having a wall at one end and open at the other end, and the other member having a portion projecting into the chamber to form an annular-like space between the portion and the chamber; a rubber insert filling said space and in simultaneous engagement with the side portions of both of said members; said portion and the member that forms the chamber being provided with means forming a rigid movable contact between the members to transmit forces in a substantially axial direction with relation to the members; said contact forming means being such that the members at the contact have limited freedom of relative lateral movement; and a pin drive between the members, there being three pins carried by one member, substantially equiangularly spaced about the axis of said one member, and corresponding clearance apertures in which the pins engage, and provided b the other member.

3. In combination: a tool carrying member; a spindle member; one of said members having a part forming a chamber having a wall at one end and open at the other end, and the other member having a portion projecting into the chamber to form an annular-like space between the portion and the chamber; a flange on said portion adjacent the said wall; a rubber insert filling said space and having its inner end in contact with said flange; said rubber insert being in simultaneous engagement with the side portions of both of said members; a retainer in contact with the outer end of the insert and carried by the member that forms the chamber, said retainer being readily removable to permit removal and replacement of the insert; said portion and the member that forms the chamber being provided, with means forming a rigid laterally movable contact between the members to transmit force in a substantiall axial direction with relation to the members; said contact formingmeans allowing bodily translation in a lateral direction of said members with respect to each other; and a positive drive means between the members.

4. In combination: a tool carrying member; a spindle member; one of said members having a part forming a chamber having a wall at one end and open at the other end; and the other member having a portion projecting into the chamber to form an annular-like space between the portion and the chamber; a flange on said portion adjacent the said wall; a rubber insert filling said space and having its inner end in contact with said flange; said rubber insert being in simultaneous engagement with the side portions of both of said members; a retainer in contact with the outer end of the insert and carried by the member that forms the chamber, said retainer being readily removable to permit removal and replacement of the insert; said portion and the member that forms the chamber being provided with means forming a rigid laterally movable contact between the members to transmit force in a substantially axial direction with relation to the members; said contact forming means allowing bodily translation in a lateral direction of said members with respect to each other; said flange having a plurality of recesses angularly spaced about the axis of the flange; and pins carried by the member that forms the chamber, and extending into the recesses for providing a positive drive between the members, said pins extending from the said wall of the chamber.

5. In combination: a tool carrying member; a spindle member; one of said members having a part forming a chamber open at one end and having a boundary surface at the other end; the other member extending into the chamber; said other member having a cooperating surface in contact with said boundar surface, at least one of the surfaces being convex to permit relative lateral, as well as angular motion between the members; and a rubber insert filling the annular-like space formed between the other member and the wall of the chamber, and in contact with the said wall and said other member.

6. In combination: a tool carrying member; a spindle member; one of said members having a part forming a chamber open at one end and having a boundary surface at the other end; the other member extending into the chamber; said boundary surface being flat, and said other member having a flat surface in contact therewith and permitting lateral movement between the members; and a rubber insert filling the space formed between the other member and the wall of the chamber, and in simultaneous contact with the said wall and said other member.

7. In combination: a tool carrying member; a spindle member; one of said members having a part forming a chamber open at one end and having a boundary surface at the other end; the other member extending into the chamber; said other member having a cooperating surface in contact with said boundary surface, at least one of the surfaces being convex to permit relative lateral, as well as angular motion between the members; a rubber insert filling the annularlike space formed between the other member and the wall of the chamber, and in contact with the said wall and said other member, said other member having a flange contacting the inner end of the resilient coupling; and means carried by the one of said members for providing a drive between the members such as to permit some relative movement between the members.

8. In combination: a, tool carrying member; a spindle member; one of said members having a part forming a chamber open atone end and having a boundary surface at the other end; the other member extending into the chamber; a ball interposed between said boundary surface and the inner end of said other member, and in contact with both said surface and said inner end; said surface and inner end permitting lateral rolling of the ball; and a rubber insert filling the annular-like space formed between the r other member and the wall of the chamber, and in contact with the said wall and said other member.

9. In combination; a tool carrying member; a spindle member; one of said members having a part forming a chamber open at one end and having a boundary surface at the other end; the other member extending into the chamber; a ball interposed between said boundar surface and the inner end of said other member, and in contact with both said surface and said inner end; said surface and inner end permitting lateral rolling of the ball; a rubber insert filling the annular-like space formed between the other member and the wall of the chamber, and in contact with the said wall and said other member; said other member having a flange contacting the inner end of the rubber insert; and means carried by the one of said members for providin a drive between the members such as to permit some relative movement between the members.

10. In combination: a tool carrying member; a spindle member; one of said members having a part forming a chamber open at one end and having a flat boundary surface at the other end of the chamber; the other member extending into the chamber and having a convex end surface contacting the boundary surface; a rubber insert filling the annular-like space formed between the other member and the wall of the chamber and in contact with the said wall and said other member; a flange carried by said other member and near the inner end of said space, said flange having a plurality of radial slots opening in the peripheryof the flange, said flange being in contact with the inner end of the rubber insert; pins carried by the part that forms the chamber and extending respectively into the slots; and a retaining ring for the rubber insert disposed at the open end of the chamber.

11. In combination: a tool carrying member; a spindle member; one of said members having a part forming a chamber open at one end and having a fiat surface at the other end of the cham ber; the other member extending into the chamber and having a flat surface contacting said first flat surface and capable of sliding relatively thereto; a rubber insert filling the annular-like space formed between the other member and the wall of the chamber and in simultaneous contact with the said wall and said other member; a flange carried by said other member and near the inner end of said space, said flange having a plurality of radial slots opening in the periphery of the flange, said flange being in contact with the inner end of the rubber insert; pins carried by the part that forms the chamber and extending respectively into the slots; and a retaining ring for the rubber insert disposed at the open end of the chamber,

' lateral rolling of the ball; a rubber insert fiiling the annular-like space formed between the other member and the Wall of the chamber and in contact with the said wall and said other member; a flange carried by said other member and near the inner end of said space, said flange having a plurality of radial slots opening in the periphery of the flange, said flange being in contact With the inner end of the rubber insert; pins carried by the part that form the chamber and extending respectively into the slots; and a retaining ring for the rubber insert disposed at the Open end of the chamber.

FRED BURG.

REFERENCES CITED The foilowing references are of record in the file of this patent:

UNITED STATES PATENTS Number Name Date 1,309,217 Ratheram July 8, 1919 1,911,670 Black May 30, 1933 2,042,648 Ziegler June 2, 1936 2,154,077 Dampson Apr. 11, 1939 FOREIGN PATENTS Number Country Date 99,133 Sweden Sept. 29, 1938 122,174 Great Britain of 1919 

